Method for maintaining a fastener in a folded configuration

ABSTRACT

A method for folding a fastener during a high speed manufacturing process and maintaining the fastener in a folded configuration throughout the high speed manufacturing process. The method includes obtaining an article that has a foldable fastener and moving the article in the machine direction during the high speed manufacturing process. The foldable fastener has first and second opposing surfaces, a web and at least one engaging member joined to the web. The method includes applying a frangible bonding agent to a first portion of the first surface of the fastening system; folding the fastening system such that the frangible bonding agent contacts a second portion of the first surface of the fastening system; and allowing the frangible bonding agent to cool at a temperature of less than 60° C.

FIELD OF THE INVENTION

A method for processing a disposable absorbent article on a high speedmanufacturing line is disclosed. More specifically, a method formaintaining a disposable absorbent article fastener in a foldedconfiguration with a frangible bonding agent is disclosed.

BACKGROUND OF THE INVENTION

Wearable absorbent articles (e.g., taped diapers, pull-on diapers,training pants, sanitary napkins, panty liners, incontinence briefs, andbandages) typically offer the benefit of receiving and containing thebodily exudates of a wearer. Disposable varieties of such absorbentarticles are commonly known, and are typically mass produced on a highspeed production line. Some disposable absorbent articles include amechanical fastening system (e.g., hook/loop or tab/slot) formaintaining the article in a desired position or configuration prior to,during, and/or after use of the article. Such fastening systems mayinclude one or more elements that extend laterally outwardly beyond theside edges of the article, such as commonly known fastening tabs. Theselaterally outwardly extending portions of the fastening system mayincrease the risk of contamination or damage to the article, an articleelement, and/or the manufacturing equipment during a high speedmanufacturing process. Repositioning the outwardly extending portions ofthe fastening system (e.g., by folding the portion laterally inward) mayreduce the likelihood of damage or contamination, but the foldedfastening system element may not remain suitably folded for a desiredamount of time (e.g., the duration of the manufacturing process) due tothe high speed nature of the manufacturing process. For example,relatively high velocities on the manufacturing line can lead tofasteners unfolding due to centrifugal forces and bending stresses asthe fasteners travel around rollers. In addition, the fasteners maycollide with stationary parts of the machine at high speeds, causing thefastening tabs to open and leaving them vulnerable to being crushed ordamaged by other rotating or stationary equipment.

A fastening system that includes a mechanical fastener having commonlyknown hooks or other similar features may be maintained in a foldedconfiguration by engaging the mechanical fastener with a complementaryelement of the fastening system, such as loops or a nonwoven portion.Such mechanical fastening systems are generally engaged by entanglingthe hooks or other similar feature with the complementary element.However, an engaged mechanical fastener still may not provide sufficientbonding strength to maintain the fastener in the desired foldedconfiguration during a high speed manufacturing process. Therefore, inorder to increase the bond strength of the mechanical fastener, abonding agent such as an adhesive may be applied to one or more portionsof the mechanical fastener prior to folding and/or engaging thefastening system. Conventional adhesives such as commonly known hot-meltadhesives generally form permanent bonds. The bond strength provided bysuch permanent bonding agents is relatively high, and may even increasefrom the time the absorbent article is made and the time it is purchasedand/or used by a consumer due to the effects of high temperaturesassociated with shipping and/or storage of the article. While permanentbonding agents may provide the desired bond strength during a high speedmanufacturing process, the increased bond strength and/or infrangibilityof the adhesive bond may be undesirable at other times such as when aconsumer attempts to use the article or fastening system and it becomesnecessary to break the bond. In order for a disposable absorbent articleto be used as intended by a consumer, it may be necessary or desirableto unfold or reposition the fastening system or other portion of thearticle. Thus, the use of a permanent bonding agent may undesirablyincrease the difficulty associated with unfolding or repositioning thefastener or other article portion. In addition, mechanical fasteningsystems are typically configured to be refastenable (i.e., the fastenercan be fastened and unfastened more than once without substantial lossof fastening capability). Applying a permanent bonding agent to themechanical fastener may undesirably reduce the refastenability of themechanical fastener, for example, by covering up the engageable portionsof the mechanical fastener with fibers or other material or even meltingthe engaging elements.

One way to address the high bond strength problems described above maybe to use a temporary bonding agent such as a temporary strengthadhesive to maintain the fastening system in a folded configuration.Temporary strength adhesives, sometimes referred to as “fugitive”adhesives, are known (see, e.g., U.S. Publication No. 2006/0027320,filed by Kueppers, et al., on June 20, 2005). However, fugitiveadhesives are typically used to create temporary, frangiblepaper-to-paper bonds, for example, for joining cardboard containersand/or portions thereof to one another, or for use with envelopes,labels, and the like. Typically, when the bond provided by a fugitiveadhesive is broken, the adhesive is no longer tacky and does not readilyadhere to anything. Fugitive adhesives are not known in the art for usein the fastening system of an absorbent article such as a disposablediaper. One reason for this may be the difference in materials used inabsorbent articles (which typically include at least some polymericmaterials as opposed to only paper). Another reason may be that thefastening system for an absorbent article is generally intended toprovide a permanent bond or, in the case of a refastenable fasteningsystem, a quasi-permanent bond to maintain the article in the desiredposition and/or configuration on a wearer. In other words, one goal ofthe fastening system is to provide sufficient bond strength to preventthe article from undesirably coming unfastened during the intended useof the article, and a temporary bonding agent will typically not helpachieve this goal.

In addition, known fugitive adhesives may not form a strong enoughinitial bond to make them capable of holding folded portions ofabsorbent articles in place during a high speed manufacturing process,during which time the folded portions of the absorbent articles couldcome in to contact with other objects in the manufacturing process. Forexample, water-based fugitive adhesives, which are typically used inlabeling and envelope applications, have relatively low bond strengthswhen wet (i.e., when applied)., and while this may be sufficient for usein bonding paper to paper, it is generally not sufficient for theabsorbent article applications described herein. Further, in order forconventional fugitive adhesives to lose strength, some fugitiveadhesives may require active heating, radiation, or the like to reducetheir strength, all of which are impractical for use with absorbentarticles. Other known fugitive adhesives are solvent cross-linkedmaterials, which may not be suitable for use in an article that contactsthe skin of a user.

Accordingly, it would be desirable to provide a method for folding afastener and maintaining the fastener in a folded configuration during ahigh speed manufacturing process. It would also be desirable to providean article comprising a folded fastening system that is relatively easyto unfold by a consumer. It would further be desirable to provide afolded fastening system which does not exhibit impaired fastenability orrefastenability after the fastener is unfolded.

SUMMARY OF THE INVENTION

In order to provide a solution to the problems set forth above, at leastone embodiment described herein provides a method for folding a fastenerduring a high speed manufacturing process and maintaining the fastenerin a folded configuration throughout the high speed manufacturingprocess. The method comprises obtaining an article comprising a foldablefastener and moving the article in the machine direction during the highspeed manufacturing process. The high speed manufacturing process has across direction orthogonal to the machine direction. The foldablefastener comprises first and second opposing surfaces, a web, and atleast one engaging member joined to the web. The method also comprisesapplying a frangible bonding agent to a first portion of the firstsurface of the fastening system. The method further comprises foldingthe fastening system such that the frangible bonding agent contacts asecond portion of the first surface of the fastening system, andallowing the frangible bonding agent to cool at a temperature of lessthan 60° C.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partial cut-away, top plan view of a disposable absorbentarticle.

FIG. 2 is a top plan view of an ear and a fastening tab.

FIG. 2A is schematic cross-section view of a fastening tab.

FIG. 2B is schematic cross-section view of a folded ear.

FIG. 3 is a partial cut-away, top plan view of a disposable absorbentarticle.

FIG. 3A is a perspective view of a disposable absorbent article.

FIG. 3B is a schematic cross-section view of a mechanical fasteningsystem.

FIG. 4 is a diagram of a manufacturing process.

FIGS. 4A-4D are top plan views of a web at various points in amanufacturing process.

FIG. 5 is a perspective view of a folding plow.

FIG. 6 is a schematic cross-section view of an ear for use in anabsorbent article.

FIG. 7 is a top plan view of a disposable absorbent article.

FIG. 7A and 7B are schematic cross-section views of the fastening tab ofFIG. 7.

FIG. 8 is a top plan view of a disposable absorbent article.

FIG. 8A is a detailed view of a fastening tab.

FIGS. 9A-9C are schematic cross-section views of a sample preparationfor the Opening Force Test.

DETAILED DESCRIPTION OF THE INVENTION Definitions:

“Absorbent article” means an article that absorbs and/or containsliquid. Wearable articles are articles placed against or in proximity tothe body of a wearer, Wearable absorbent article are absorbent articlesplaced against or in proximity to the body of a wearer to absorb andcontain various exudates discharged from the body. Nonlimiting examplesof wearable absorbent articles include diapers, pant-like or pull-ondiapers, training pants, sanitary napkins, tampons, panty liners,incontinence devices, and the like.

“Comprising” means that the various components, ingredients, or steps,can be conjointly employed in practicing the disclosed fastening systemprocess. Accordingly, the term “comprising” encompasses the morerestrictive terms “consisting essentially of” and “consisting of.”

“Disposable” means absorbent articles which generally are not intendedto be laundered or otherwise restored or reused as an absorbent article(i.e., they are intended to be discarded after a single use and,preferably, to be recycled, composted or otherwise disposed of in anenvironmentally compatible manner).

“Disposed” means the placement of one element of an article relative toanother element of an article. For example, the elements may be formed(joined and positioned) in a particular place or position as a unitarystructure with other elements of an article or as a separate elementjoined to another element of the article. When one element is disposedon another element, the elements or portions thereof may be in directcontact with one another, or the elements or portions thereof may beseparated, for example, by the joining means (e.g., adhesive).

“Engage” and variations thereof mean to join two or more elements to oneanother in a cooperative fashion. For example, a hook/loop typemechanical fastening system may be engaged by entangling the hooks andloops with one another. In another example, two substrates may beengaged by applying an adhesive to one or both substrates and contactingthem with one another. In yet another example, a hook/loop typemechanical fastening system may be engaged by applying an adhesive tothe hooks of the fastening system and contacting the adhesive withanother element, which may or may not include loops, such that the hookcontaining portion of the fastening system and the contacted substrateare joined to one another due, at least partially, to the adhesive.

“Elastic” means the property of a material or component (e.g., film,fiber, nonwoven, strand, laminate or combinations of these) to elongate,without rupture or breakage, by at least 50% at a load of between 0.1and 10 N/cm in the Hysteresis Test described in detail in copending U.S.Application Ser. No. 12/398,615. Further, upon release of the load, theelastic material or component has set less than or equal to 20% asmeasured according to the aforementioned Hysteresis Test. For example,an elastic material that has an initial length of 25 mm can elongate toat least 37.5 mm (50% elongation) and, upon removal of the force,retract to a length of 27.5 mm, i.e., have a set of 2.5 mm (10% set). Itis to be understood, however, that this definition of elastic does notapply to materials such as individual elastic strands that do not havethe proper dimensions (e.g., not wide enough) to be properly subjectedto the hysteresis test. Instead, such material is considered to beelastic if it can elongate to at least 50% upon application of a biasingforce, and return substantially to its original length (i.e., exhibitless than 20% set) upon release of the biasing force.

“Extensible” material is material that elongates, without rupture orbreakage, by at least 50% at a load of between 0.1 and 10 N/cm in theHysteresis Test set forth in copending U.S. Application Ser. No.12/398,615. Further, upon release of the load, the material has greaterthan 20% set, as measured according to the aforementioned HysteresisTest. For example, an extensible material that has an initial length of25 mm can elongate at least to 37.5 mm (50% elongation) and, uponremoval of the applied force, retract to a length of 35 mm, i.e., have aset of 10 mm (40% set), when subjected to the aforementioned HysteresisTest.

“Film” means a substantially nonporous material made by a process thatincludes extrusion of, e.g., a polymeric material through a relativelynarrow slot of a die. A film may be impervious to a liquid and perviousto an air vapor, but need not necessarily be so.

“Foldable” means that a component can be bent such that one portion ofthe component can be placed over another portion of the same componentin an overlaying relationship without permanently altering its abilityto function as intended.

“Frangible Bond” means a bond that through deformation tends to breakrelatively easily via cohesive failure, rather than deformingplastically (i.e., extensibly) and retaining its cohesion as a singleobject. Frangible bonds are sometimes referred to as being brittle, andare generally designed to be broken by a user at some point during theuse of an article comprising the frangible bond. “High speedmanufacturing process” means a manufacturing process that is capable ofproducing more than 400 products per minute.

“Joined” means configurations whereby an element is directly secured toanother element by affixing the element directly to the other element(e.g., ultrasonic bonding, thermal bonding, high pressure bonding andthe like), and configurations whereby an element is indirectly securedto another element by affixing the element to intermediate member(s)that in turn are affixed to the other element (e.g., adhesive bondingwhere the adhesive is the intermediate member).

“Longitudinal” means a direction running substantially perpendicularfrom a waist end edge to an opposing waist end edge of an absorbentarticle when the article is in a flat out, uncontracted state, or from awaist end edge to the bottom of the crotch in a bifolded article.Directions within 45 degrees of the longitudinal direction areconsidered to be “longitudinal.” “Lateral” refers to a direction runningfrom a side edge to an opposing side edge of an article and generallyperpendicular to the longitudinal direction. Directions within 45degrees of the lateral direction are considered lateral.

“Machine direction” (“MD”) is the direction parallel to the direction oftravel of the web in a manufacturing process. Directions within 45degrees of the MD are considered to be machine directional. The “crossmachine direction” (“CD”) is the direction substantially perpendicularto the

MD and in the plane generally defined by the web. Directions within 45degrees of the CD are considered to be cross directional.

“Nonwoven” means a porous, fibrous material made from continuous (long)filaments (fibers) and/or discontinuous (short) filaments (fibers) byprocesses such as spunbonding, meltblowing, carding, and the like.Nonwovens do not have a woven or knitted filament pattern. Nonwovens maybe liquid permeable or impermeable.

“Outboard” and “inboard” mean, respectively, the location of an elementdisposed relatively far from or near to the longitudinal centerline ofan absorbent article with respect to a second element. For example, ifelement A is outboard of element B, then element A is farther from thelongitudinal centerline than is element B. Similarly, “outward” and“inward” mean, respectively, directions which are away from or towardthe longitudinal centerline.

“Refastenable” means the ability of two or more elements or portions ofelements, which are fastened together, to be unfastened and refastenedwithout substantial degradation of fastener performance or damage tosurrounding components of the article that would impair the article'scontinued use.

“Web” means a material capable of being wound into a roll. Webs may befilms, nonwovens, laminates, apertured laminates, and the like.

“X-Y plane” means the plane defined by the MD and CD of a moving web orthe length and width of a piece of material.

Disposable Absorbent Article

FIG. 1 shows a partial cut-away, plan view of a diaper 10 in a flat-out,uncontracted state (i.e., with no elastic induced contraction). Portionsof FIG. 1 are cut away to more clearly show the construction of thediaper 10. The diaper 10 may also include a first waist region 56, asecond waist region 58, and a crotch region 57 disposed therebetween.The diaper 10 may have a periphery 53 defined by opposing longitudinalside edges 55A and 55B and opposing end edges 59A and 59B.

The inner, wearer-facing surface 52 of the diaper 10 is oriented towardsthe viewer and the opposing outer, garment-facing surface is orientedaway from the viewer. As shown in FIG. 1, the diaper 10 may include aliquid pervious topsheet 30; a liquid impervious outer cover 20 joinedwith at least a portion of the topsheet 30, for example, along theperiphery 53 of the diaper 10; and an absorbent core assembly 40positioned between the topsheet 30 and the outer cover 20. The diaper 10may include an elastic waist feature 60 and a fastening system. Thefastening system may include an ear 65 joined to at least one waistregion 56 and/or 58. In certain embodiments, the ear 65 and one or bothwaist regions 56 and/or 58 may be formed from as a unitary structure.The ear 65 may include a fastening tab 70, which extends laterallyoutwardly from the diaper 10 and an engaging member 71 disposed on thefastening tab 70. The engaging member 71 may be engageable with anotherportion of the diaper 10 (e.g., another portion of the ear 65 and/or areceiving member). “Engageable” means one element is configured to bejoined to another element, for example, through the creation of anentanglement-type mechanical bond. The fastening tab 70 may include agripping portion 73 that enables a user to grasp and/or manipulate thefastening tab 70. The gripping portion 73 may extend laterally outwardlyfrom the edge of the engaging member 71 at a distance of greater than 0mm, for example between 0 and 20 mm. The inner, wearer-facing surface 52of the diaper 10 may include at least a portion of the topsheet 30 andother components, which may be joined to the topsheet 30. The outer,garment-facing surface may include at least a portion of the outer cover20 and other components, which may be joined to the outer cover 20. Thediaper may include a longitudinal centerline 11 and a lateral centerline12 orthogonal thereto. Nonlimiting examples of absorbent articles andabsorbent article components are described generally in U.S. Pat. Nos.3,860,003; 5,151,092; 5,221,274; 5,554,145; 5,569,234; 5,580,411;6,004,306; 5,938,648; 5,865,823; and 5,571,096.

Fastening System

Known mechanical fastening systems (i.e., fastening systems that formmechanical bonds between themselves and/or another component whenfastened) include hook/loop type mechanical fastening systems andtab/slot type mechanical fastening systems. Other examples of mechanicalfastening systems include, without limitation, hermaphroditic, friction,static, magnetic, button/button hole, zippers, buckles and the like.Examples of mechanical fastening systems and configurations ofmechanical fastening systems may be found in U.S. Pat. Nos. 4,662,875;4,846,815; 4,894,060; and 6,432,098; and PCT Publication No.WO92/022273. Hook/loop type mechanical fastening systems typicallyincludes an engaging member comprising hooks and a complementaryreceiving member comprising loops. The hooks engage the loops, typicallythrough entanglement, to form a mechanical bond. In certain embodiments,the engaging member may comprise a base for providing a relativelystrong backing that the hooks can be imbedded, bonded, woven or fusedinto. The hooks and the base may be formed from a single piece ofmaterial (e.g., as described in U.S. Pat. No. 6,478,784 issued toJohnson, et al.), or the hooks and the base may be discrete componentsthat have been joined to one another by any means known in the art. Thebase or portions thereof may be flexible or stiff, as desired, forexample, by including a stiffening element. The base may be manufacturedfrom a wide variety of materials commonly used for backings formechanical fasteners (e.g., nylon, polypropylene, polyethylene, or anyequivalent material or blends of these materials). In certainembodiments, the base may be a woven nylon material secured to anonwoven or a film member by an adhesive and/or other commonly knownbonding means. The base may have an engaging side and a non-engagingside opposed thereto. The non-engaging side of the base may bepermanently joined to a fastening tab or another component of theabsorbent article, such as a waist panel, side panel, or ear. The hooksgenerally project out of the engaging side of the base, and each hookhas a proximal end joined to the engaging side of the base and a distalend spaced away from the proximal end. The distal and proximal ends ofthe hook may be connected with a stem that extends between the two ends.The shape of the hooks may be selected to provide a suitable amount ofentanglement with complementary receiving elements. Nonlimiting examplesof suitable engaging element shapes include hook-shaped,mushroom-shaped, and t-shaped. Suitable examples of engaging membermaterials include commercially available hook material from Aplix, soldunder the product codes 963, 960, 957, and 942, and 3M, sold under theproduct codes CS200, CS300, CS600, or MC6. One example of a suitablereceiving member material is sold by 3M as product code KLT. Anotherexample of suitable receiving member material is product #18904 sold byGuilford located in Wilmington, N.C. In certain embodiments, thereceiving member may simply be a nonwoven web (e.g., a single layer ofnonwoven or a laminate with at least one nonwoven surface or surfaceportion). Nonwovens are typically formed from a multitude of fibersarranged in a substantially random pattern. This random arrangement offibers may provide sufficient loop formations or other similar featureson the surface of the nonwoven, which are capable of desirably engagingwith the engaging elements (e.g., hooks) of an engaging member. Suitableexamples of mechanical fastening systems and elements thereof aredisclosed in copending U.S. Provisional Ser. No. 61/184,102, filed onJun. 4, 2009 by Kline. U.S. Pat. Nos. 5,032,122, 5,326,612, and7,416,545; and PCT Publication Nos. WO07/096841, WO07/096842,WO96/022065, WO96/004812 WO07/072421, WO07/072386, and WO07/069227.WO07/036908; WO03/105740, WO99/11211 and WO99/11212.

FIG. 2 shows an exemplary embodiment of an ear 265 for use with, forexample, a disposable absorbent article. The ear 265 may include afastening tab 270 that extends laterally outwardly from the ear 265. Thefastening tab 270 may include an engaging member 271, which includes aplurality of engaging elements 274, and a gripping portion 273 thatextends laterally outwardly from the engaging member 271 (i.e., in thex-direction) to define the outer edge 277 of the fastening tab 270. Theengaging elements 274 may have a frangible bonding agent 230 disposedthereon. In certain embodiments, the frangible bonding agent 230 may beapplied to another portion of the ear 265 (e.g., the corrugated portion290, attachment edge 291, and/or in the vicinity of folding lines 285and/or 286) such that the engaging elements 274 may be contacted withthe frangible bonding agent 230 by folding the ear 265 and/or fasteningtab 270. Alternatively or in addition to the embodiments describedabove, the frangible bonding agent 230 may be applied to the grippingportion 273, for example, by using more than one applicator (e.g., afirst glue gun for applying the frangible bonding agent 230 to a firstlocation and a second glue gun for applying the frangible bonding agent230 to the gripping portion 273 or other second location). The ear 265may include a support member 280 that supports one or more otherelements of the ear 265 and/or fastening tab 270 (e.g., the engagingmember 271). The support member 280 may include a nonwoven or filmmaterial as the outer layer of an extensible or elastic multilayerlaminate structure. In an alternative example, the support member 280may be formed as a single layer of extensible or elastic nonwoven orfilm material. In certain embodiments, the support member 280 mayinclude a stiffened region of higher density and/or basis weightmaterial to increase the stability of the fastener when it is engaged(e.g., reduce buckling). The ear 265 may include an attachment edge 291,along which the ear 265 may be joined to an article or article component(e.g., a side panel or absorbent article chassis). The engaging elements274 are typically engageable with another portion of the ear 265 (e.g.,the support member 280 or corrugations 290 formed in the support member280) and/or receiving elements disposed elsewhere on the article. Incertain embodiments, the fastening tab 270 may be folded over itself(e.g., along first folding line 285, second folding line 286, or anyother portion of the fastening tab 270 or ear 265, as desired) such thatthe engaging elements 274 contact at least a portion of the supportmember 280. In certain embodiments, the fastening tab 270 may beelastic. That is, the fastening tab 270 may be stretched beyond itsoriginal length by a tensile force and when the tensile force isremoved, the fastening tab 270 exhibits less than 20% set (i.e.,exhibits at least 80% recovery). The elasticity of the fastening tab 270may be provided by a plurality of corrugations 290 formed in the supportmember 280, for example, by a commonly known incremental stretchingprocess (“activation” or “ring rolling”). Additionally or alternatively,an extensible nonwoven may be joined with an elastic material such asone or more elastic strands and/or an elastic film or nonwoven materialto form an elastic laminate material. The nonwoven may be joined to anunstrained (i.e., relaxed) elastic material before, during, or after anactivation process to form a so-called zero-strain stretch laminate, orjoined to a strained (i.e., stretched) elastic material to form aso-called live-stretch laminate.

FIG. 2A shows an exemplary embodiment of a fastening tab 270 along lineA-A of FIG. 2. The engaging elements 274 in FIG. 2A are shown as beinghook-shaped, however, it is to be understood that the engaging elements274 may be any suitable shape desired. The fastening tab 270 may includea support member 280 formed as a laminate comprising an upper and alower nonwoven layer 281 and 283. The fastening tab 270 may include thesupport member 280 and/or one or more additional nonwoven and/or filmcomponents. The base 275 of the engaging member 271 may be joined to theupper nonwoven layer 281, for example, by adhesive layer 202. Thebonding agent 230 may be applied to the heads 272 of the engagingelements 274 as a substantially unbroken line that spans the gaps 225between adjacent engaging elements 274. When the bonding agent 230 isapplied as a molten composition, the bonding agent 230 may penetrate atleast partially into one or more of the gaps 225, but remainssubstantially continuous (i.e., unbroken). FIG. 2B shows an exemplaryembodiment of the ear 265 and fastening tab 270 of FIG. 2 in a foldedconfiguration. As shown in FIG. 2B, the fastening tab 270 is folded overitself in the x-direction along folding line 286. The entire engagingmember 271 or a substantial portion thereof (e.g., a majority of thehooks 274) may contact the corrugated portion 290 of the ear 265 in anoverlaying configuration. In certain embodiments, however, no portion ofthe engaging member 271 need contact the corrugated portion 290. Thefastening tab 270 and/or ear 265 may be folded in any suitableconfiguration desired. For example, the fastening tab 270 and/or ear 265may be folded more than once in the same or different direction(s)(e.g., inwardly and/or outwardly). In certain embodiments, the fasteningtab 270 may be folded such that a portion of the fastening tab 270 stillextends laterally outwardly past the longitudinal side edge of thearticle, but to a lesser extent than before it was folded.

FIG. 3 shows an exemplary embodiment of a disposable absorbent article500 in a flat-out, uncontracted state (i.e., with no elastic inducedcontraction). The article 500 may include a slot/tab type mechanicalfastening system 570 positioned at the front and/or rear waist regions536 and 538. The fastening system 570 may include one or more tabmembers 42 and one or more slot members 44. The slot members 44 may eachhave one or more slots 46 configured to pass at least a portion of thetab member 42 therethrough. FIG. 3A shows the disposable absorbentarticle 500 of FIG. 3 in a fastened configuration (i.e., the fasteningsystem 570 is engaged). As shown in FIG. 3A, at least one of the tabmembers 42 is passed through a slot 46 of at least one of the slotmembers 44 to join the front waist region 536 and the rear waist region538 of the article 500 to one another, thereby providing a waist opening550 and at least one leg opening 551. The tab members 42 may be joinedto the article 500 or a component thereof (e.g., side panel) along aline of attachment 72. The tab member 42 may include a retaining elementthat helps to keep the fastening system 570 from disengaging. Theretaining element may include a raised portion, a lowered portion, anotch, a lip, a rough portion, combinations of these and the like toprevent or at least inhibit the tab member 42 from undesirably slippingback through the slot member 44.

FIG. 3B shows an exemplary slot/tab type mechanical fastening system1000. The fastening system 1000 may include a slot member 1044 and a tabmember 1042, each joined to a support member 1028 (e.g., a commonlyknown nonwoven and/or film material). The slot member includes a slot1046 configured to pass the tab member 1042 therethrough. The supportmember 1028 may be joined to or be part of another article component(e.g., a side panel of a disposable diaper). In certain embodiments, thefastening system may include a bonding agent 1030 disposed on acomponent of the fastening system (e.g., the tab member 1042, the slotmember 1044, and/or the support member 1028). For example, the bondingagent 1030 may be disposed on the tab member 1042 such that the tabmember 1042 may be joined to itself or another component of thefastening system 1000 (e.g., slot member 1044 and/or support member1028).

Frangible Bonding Agent

A frangible bonding agent is a bonding agent capable of forming afrangible bond suitable for use in the articles and/or fastening systemsdisclosed herein. In certain embodiments, the frangible bonding agentmay comprise an adhesive such as, for example, a fugitive hot-meltadhesive. A fugitive adhesive is generally understood to be an adhesivethat exhibits a decaying bond strength (i.e., has a predictable decreasein bond strength over time). The initial bond strength of a bond formedby a fugitive adhesive is generally limited by the adhesive attractionbetween the adhesive and the substrate(s) to which it is applied (i.e.,the intermolecular attraction between the adhesive and the substrate).However, after a fugitive adhesive crystallizes, the bond strength ofthe bond is generally limited by the cohesive strength of the adhesive,which is typically less, and in some instances substantially less, thanthe adhesive strength of the bond. One particularly suitable example ofan adhesive for use herein comprises a copolymer of 1-butene in anamount ranging from 10% to 80% by weight based on the weight of theadhesive (e.g., PB-1 available from Basell), wax in an amount of 5% to60% by weight, based on the weight of the adhesive, and from 55 to 25%of a tackifying resin. It may be desirable to provide the wax as amixture of high melt point and low melt point waxes in a ratio of 1:7 to1:1 (high melt point to low melt point). It is believed, without beinglimited by theory that this ratio may provide a suitable crossovertemperature for the adhesive. Due to the wide range of environmental andprocessing conditions to which disposable absorbent articles may beexposed, a crossover temperature (T_(x)) of greater than 50° C.; forexample, between 50°-70° C.; between 55°-65° C.; between 58°-62° C.; oreven 60° C. may be suitable for certain adhesives described herein.T_(x) is the temperature at which a hot-melt adhesive has the sameapparent elastic modulus (G′) and apparent viscous modulus (G″). TheT_(x) of an adhesive or other polymeric material may be determinedaccording the Rheological Measurement Test detailed below.

At temperatures below the T_(x) of an adhesive, the adhesive may be moredifficult or expensive to process (e.g., the adhesive does not flow aswell or at all or additional energy must used), resulting in a smallerprocess window. Therefore, an adhesive that has a relatively low T_(x),such as a conventional fugitive adhesive, may have desirable processingcharacteristics. However, at temperatures above the T_(x), of such anadhesive, which may occur during transport and/or storage of an articlecomprising the adhesive, the adhesive may exhibit a greater tendency toflow and may penetrate further into the substrate to which it isapplied, thereby causing an undesirable increase in bond strength. It isbelieved that the bonding agents disclosed herein may provide a solutionto this problem. Table 1 below shows a comparison of crossovertemperatures for various adhesives. Fugitive hot-melt adhesives aretypically applied to a substrate at a temperature greater than thecrossover temperature of the adhesive. Suitable fugitive hot-meltadhesives for use herein may exhibit a peak adhesive bond strengthwithin one hour of application. Once the fugitive hot-melt adhesivecools, it typically begins to crystallize and may exhibit a decayingbond strength. As mentioned above, it is believed, without being limitedby theory, that the decaying bond strength is due to the transition ofthe bond failure mode from adhesive failure to cohesive failure (i.e.,the fugitive adhesive forms a frangible bond). Suitable bond strengthdecays for a fugitive adhesive include a loss of greater than or equalto about any of the following amounts of initial bond strength: 20%,30%, 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100%. Thebond strength decay of a fugitive adhesive may be determined accordingto the Coupon Peel Test described below.

In certain embodiments, a bonding agent that does not form a frangiblebond, but exhibits a suitable decaying bonding strength may be usedherein. In such embodiments, the bonding agent may fail adhesively orcohesively as long as suitable bonding forces and fastener performanceare provided.

Process For Providing an Improved Fastening System.

A frangible bonding agent may be applied to one or more portions of thefastening systems described herein (e.g., the fastening tab, engagingmember and/or engaging elements). The fastening system may then befolded such that the frangible bonding agent, by itself or incombination with another fastening mechanism, joins one portion of thefastening system to another portion. For example, a frangible bondingagent may be applied to at least some of the heads of hook-type engagingelements in a hook/loop type fastening system. In such an example, thefastening tab may be folded over such that the frangible bonding agentand optionally the hooks contact another portion of the same surface ofthe fastening tab. In another example, a frangible bonding agent may beapplied to the tab member of a slot/tab type mechanical fasteningsystem, and the tab member may be positioned such that frangible bondingagent contacts the slot member, and/or other portions of the fasteningsystem or article. When applying the frangible bonding agent to afastening system, it may be desirable to apply the frangible bondingagent such that it does not interfere with the ability of the fasteningsystem to be fastened and/or refastened as intended. For example,applying a frangible bonding agent to a relatively large number of hooksin a refastenable hook/loop type fastening system may interfere with theability of the hooks to engage with the corresponding loops of thereceiving member. Thus, it may be desirable to apply the frangiblebonding agent to 10% or less of the hooks (e.g., 9%, 8%, 7%, 6%, 5%, 4%,3%, 2%, or even less than 1%, but greater than 0%), as measured by the %surface area of the hook-containing portion of the engaging member thatincludes the frangible bonding agent. The frangible bonding agent may beapplied as an unbroken strand or film that extends between two morehooks. In certain embodiments, the frangible bonding agent may beapplied as a layer of relatively fine meltblown fibers. The frangiblebonding agent may be applied in any suitable linear or nonlinear patternsuch as, for example, a pattern that resembles one or more straightlines, one or more broken lines, S-shapes, T-shapes, X-shapes,omega-shapes, dots, circles, rectangles, spirals, combinations of theseand the like. In one suitable example, the frangible bonding agent maybe applied as substantially straight line (i.e., bead) of fugitivehot-melt adhesive that has a length of between 1% and 100%; 1 and 50%; 1and 40%; or even 1 and 20% of the length of the engaging member. Inorder to potentially minimize the effect of the frangible bonding agenton the ability of the fastener to be fastened or refastened, thefrangible bonding agent may be applied as a relatively narrow linehaving a width of between 0.1% and 30%; 1 and 25%; 1 and 15%; or even 1and 10% of the width of the engaging member. Of course, the frangiblebonding agent may have any length or width desired, as long as suitablebond strength and fastener performance is obtained. In certainembodiments, the frangible bonding agent may be contiguous with one ormore of the edges of the engaging member and/or fastening system. Forexample, the frangible bonding agent may extend from one edge of theengaging member to another edge in the MD, CD, and/or diagonally, or thefrangible bonding agent may extend from one edge of the engaging memberand/or fastening system to an inner portion of the engaging memberand/or fastening system (i.e., a portion disposed between two edges),but not to another edge. In certain embodiments, the frangible bondingagent may be disposed adjacent to the engaging member rather than on theengaging member so as to reduce or even eliminate any undesirable impactthat the frangible bonding agent may have on the intended mechanicalbonding function of the fastening system (e.g., fouling of the hooks).In certain embodiments, the frangible bonding agent may be disposed on asurface of the fastening system to which the engaging member is to bejoined. For example, the frangible bonding agent may be applied to anonwoven surface of an ear and/or fastening tab, such that when thefastening tab is folded the engaging member comes into contact with thefrangible bonding agent. In certain embodiments, the frangible bondingagent may be disposed on both the engaging member and one or more otherportions of the fastening system. For example, the frangible bondingagent may be applied as a single line of adhesive disposed on both theengaging member and a portion of the ear and/or fastening tab adjacentthe engaging member. In another example, the frangible bonding agent maycomprise a first line of adhesive disposed on the engaging member and asecond line of adhesive disposed on another portion of the fasteningsystem spaced apart from the first line and/or the engaging member. Inyet another example, the frangible bonding agent may be formed byapplying a first composition to a first portion of a substrate and asecond composition to a second portion of the same substrate and thenbringing the two portions of the substrate together, such that the twocompositions contact one another and form a frangible bond.

In this example, the first and second composition need not necessarilybe capable of forming a frangible bond individually, as long as afrangible bond is formed when they are combined. Other suitable examplesof patterns and configurations for applying the frangible bonding agentare described in U.S. Pat. No. 6,701,580 and U.S. ProvisionalApplication Ser. No. 61/184,102.

FIG. 4 shows an example of an exemplary high speed process 300 forfolding a fastening system and maintaining the fastening system in afolded configuration. Elements 4A, 4B, 4C, and 4D, represented bybroken-line circles, indicate particular positions in the process 300that are shown in more detail in FIGS. 4A, 4B, 4C, and 4D, respectively.A substrate 303 is fed into the process 300, for example, by unwinding acontinuous web from a supply roll 310 and placing the web on an endlessconveying means 380 (e.g., a conveyor belt). In certain embodiments, thesubstrate 303 may be unwound from a roll and pulled into a converterwith a combination of driven rollers, undriven rollers (“idlers”),and/or a rolling nip. In certain embodiments, the substrate 303 may befed into the process 300 from one or more other upstream processes. Thesubstrate 303 may be a single layer of nonwoven or film material or,alternatively, the substrate 303 may be a laminate material formed byjoining one or more webs of material together in a face-to-facerelationship. One particularly suitable example of a substrate 303includes the stretchable laminate 410 illustrated in FIG. 6. Thesubstrate 303 may be configured for use as a support member such as, forexample, the support member 280 in FIG. 2. The conveying means 380 movesthe substrate 303 in the MD to a position where engaging member material311 is placed on the substrate 303 to form a composite web 308. Theengaging member material 311 may be provided by a supply roll 313 orfrom an upstream process in the form of a continuous web of material oras discrete engaging members, and may be joined to the substrate 303 byany suitable means known in the art (e.g., adhesive bonding, cohesivebonding, ultrasonic bonding, thermal bonding, high pressure bonding,combinations of these and the like). The composite web 308 is moved inthe MD to the bonding agent application station 320. At the bondingagent application station 320 a frangible bonding agent 323 is appliedto the composite web 308. The frangible bonding agent 323 may be appliedto one or more portions of the engaging member material 311 and/or thesubstrate 303. The frangible bonding agent 323 may be provided in theform of a fugitive hot-melt adhesive and may be applied by any suitablemeans known in the art (e.g., spraying, coating, slot-coating,extruding, meltblowing). For example, the frangible bonding agent 323may be applied with an eDot brand hot-melt adhesive applicator,available from Nordson Corporation. The frangible bonding agent 323 maybe applied as a relatively narrow continuous line or intermittent linehaving a width in the CD of between 0.1% and 30%; 1 and 25%; 1 and 15%;or even 1 and 10% of the width of the engaging member. the frangiblebonding agent 323 may be applied as a continuous line having a length ofbetween 1% and 100%; 1 and 50%; 1 and 40%; or even 1 and 20% of thelength of the engaging member. Alternatively, the frangible bondingagent 323 may be applied as a series of 2 or more intermittent lines,each line having a length in the MD of between 1 mm and 50 mm. WhileFIG. 4 shows the process 300 as including only one bonding agentapplication station 320, it is to be appreciated that the process 300may include more than one bonding agent application station 320 (e.g.,2, 3, 4, 5, or more) and/or the process 300 may include multipleapplicators of the same or a different type in a single bonding agentapplication station 320 for applying the frangible bonding agent 323 inany pattern or combination of patterns desired. Downstream from thebonding agent application station 320 is a cutting station 330. At thecutting station 330, the composite web 308 may be separated into one ormore discrete fasteners 355 or webs of fasteners 355. For example, thecomposite web 308 may be separated into two parallel webs of fasteners355, as shown in FIG. 4C. The cutting station 330 may include a meansfor separating the composite web 308 into fasteners 355 having aparticular shape or pattern (e.g., one or more knife rolls,reciprocating knives, scissors, plates, dies, embossing rolls, highpressure rolls, thermal cutters, ultrasonic cutters, laser cutters, orother known cutting tools or separating means). The cutting station 330may also include a means for removing any excess or undesired material,which is sometimes referred to as trim or scrap, from the separated web.For example, the cutting station may use compressed air or vacuum toremove the trim from the moving line. Downstream from the cuttingstation 330 is a folding station 340 for folding the incoming webs offasteners 355. In certain embodiments, the fasteners 355 are foldedlaterally inwardly at least once, such that the frangible bonding agent323 contacts another portion of the fastener 355. Alternatively, thefasteners 355 may be folded two or more times. In certain embodiments,the folding station 340 may include a folding plow 341, as shown in FIG.5. The folding plow 341 has a leading edge 342 for contacting the websof fasteners 355 moving in the MD. When the webs of fasteners 355contact the leading edge 342 of the folding plow 341, the fasteners 355are moved to one side of the plow 341 or the other, depending on theorientation of the fastener. As the webs of opposing fasteners 355 movepast their respective sides of the plow 341, a portion of each fastener355 is folded over itself in the CD. Exemplary systems for foldingvarious absorbent article components, including fasteners, are wellknown in the art (e.g., U.S. Pat. No. 5,714,027 issued to Taub). Uponexiting the folding station 340, the folded fasteners 355 pass through apair of compression rolls 335, which apply pressure to the foldedfasteners 355. The pressure applied by the compression rolls 335 tendsto distribute the frangible bonding agent 323 across or into thecomponent(s) that are to be bonded (e.g., by spreading the agent 323across a surface or pushing the agent 323 further into a fibrousmatrix). In certain embodiments, the compression rolls 335 may be usedto at least partially engage complementary engageable members of amechanical fastening system such as, for example, a hook/loop typemechanical fastening system. After being compressed, the webs of foldedfasteners 355 may be spaced further away from one another in the CD andaligned with one another in the MD. In other words, opposing fastenersmay be positioned to be directly across from each other in the CD, asopposed to the “staggered” positioning shown in FIGS. 4C and 4D). Thewebs of fasteners 355 may then be wound onto a roll or festooned into abox for later use or sent directly to a downstream process where theymay be incorporated into an article.

FIG. 4A shows a composite web 308 at position 4A in the process 300 ofFIG. 4. As seen in FIG. 4A, the substrate 303 has the engaging membermaterial 311 joined thereto. The substrate 303 may include activatedregions 315 for providing elastic extensibility in the CD. In certainembodiments, it may be desirable to position the engaging membermaterial 311 to be substantially equidistant from the longitudinal sideedges 306 of the substrate 303.

FIG. 4B shows a composite web 308 at position 4B in the process 300 ofFIG. 4. As seen in FIG. 4B, a frangible bonding agent 323 has beenapplied to the engaging member material 311 in the form of anintermittent line comprising a plurality of line segments. Each linesegment has a length in the MD and a width in the CD. While the bondingagent 323 is shown as being disposed on the engaging member material311, it is to be understood that the bonding agent may also be appliedto one or more portions of the activated region 315, substrate 303, orany other portion of the composite web 308, as desired.

FIG. 4C shows a composite web 308 at position 4C in the process 300 ofFIG. 4. As seen in FIG. 4C, the composite web 308 has been separatedinto two parallel webs of fasteners 355. During the separation of thecomposite web 308, material (e.g., scrap or trim) is removed from thecomposite web 308 to form spaces 382 between the webs of fasteners 355.The webs of fasteners 355 are shown in FIG. 4C as being “staggered” or“offset” from one another in the MD. Alternatively, the parallel webs offasteners 355 may be configured as mirror images of one another.

FIG. 4D shows a composite web 308 at position 4D in the process 300 ofFIG. 4. As seen in FIG. 4D, The fasteners 355 have been folded laterallyinwardly (i.e., in the CD), but are still staggered in the MD and inrelative close proximity to one another.

FIG. 6 shows an example of a substrate 400 suitable for use as an earsuch as, for example, the ear 265 shown in FIG. 2. The substrate 400 mayinclude a multi-layer laminate material 410 and an engaging member 471.The engaging member 471 may include one or more engaging elements 474joined to a base 475. The engaging member 471 may be joined to thelaminate material 410 by any suitable means known in the art. Thelaminate material 410 may include a first and second nonwoven layer 481and 483. The first and second nonwoven layers 481 and 483 may be formedfrom any suitable plastic (i.e., extensible), elastic, or plasto-elasticfibers known in the art. Suitable materials for forming the fibersinclude natural and synthetic materials such as cellulose, cotton,rubber, extensible or elastic polyolefins (e.g., polypropylene,polyethylene, polybutylene), polyurethanes, nylon, combinations of theseand the like. The fibers may be monocomponent or multi-component (e.g.,core/shell, side-by-side, or sea/island type bicomponent fibers). Oneparticularly suitable example of a fiber includes a core/shell typebicomponent fiber where the shell is formed from extensible polyethyleneand the core is formed from an elastic polypropylene (e.g., VISTAMAXXbrand polypropylene resin, available from Exxon Mobil Chemical). Thenonwoven layers 481 and 483 may each be configured as a single layer ofmaterial or as a multi-layer laminate. For example, the first nonwovenlayer 481 may be a layer of carded fibers having a basis weight ofbetween 15 and 40 grams per square meter (“gsm”), and the secondnonwoven layer 483 may be a three-layer SMS (i.e.,spunbond-meltblown-spunbond) laminate having a total basis weight ofbetween 8 and 30 gsm. One or both of the nonwoven layers 481 and 483 mayinclude one or more activated portions 415, which provide some degree ofelasticity and/or reduced resistance to stretch. The activated portions415 may be provided by any suitable activation technique known in theart, such as one or more of the methods described in U.S. Pat. Nos.4,200,963; 4,209,563; 4,525,407; 4,834,741; 5,143,679; 5,650,214;5,156,793; 5,330,458; and 6,476,289. Sandwiched between the nonwovenlayers 481 and 483 is a film layer 482. The film layer 482 may be formedfrom any suitable elastic or extensible material known in the art. Incertain embodiments, the film 482 may be formed from an extensiblematerial and subjected to a process for providing elasticity to the film482, such as a commonly known SELFing process described in U.S. Pat.Nos. 5,518,801 and 5,554,145. The film layer 482 may be joined to one orboth nonwoven layers 481 and/or 483 by any suitable means known in theart. The laminate material 410 may include an optional stiffener layer465. The stiffener layer 465 may be formed from a high basis weightnonwoven such as, for example, a 30-100 gsm spunbond nonwoven. Suitableexamples of stiffener layers are described, for example, in U.S.Publication Nos. 2007/0143972 and 2007/0157441.

In certain embodiments, a fastening system may include one or morediscrete tape tabs that extend laterally outwardly from one or bothlongitudinal edges of the fastening system and/or the article comprisingthe fastening system. The tape tabs may be joined to a fastening systemthat is in turn joined to an article or, alternatively, the tabs may bejoined directly to the article. The tape tabs generally include anengaging element that is configured to attach to a receiving elementsuch as a commonly known landing zone. Suitable examples of tape tabsand ear configurations are disclosed in PCT Publications Nos.W007/072421; W007/072386; and W007/069227; and U.S. Pat. No. 7,416,545.

FIG. 7 shows an example of an absorbent article 760 that includes foldedtape tabs 770 disposed along opposing longitudinal side edges 761 of thearticle 760. FIGS. 7A and 7B show the folded tape tabs 770 of FIG. 7along lines A-A and B-B, respectively. When unfolded, the tape tabs 770may extend laterally outwardly from the article 760 (i.e., in thex-direction). The tape tabs 770 may each include an engaging member 771and a one or more frangible bonding agents 772. In the example shown inFIG. 7A, the tape tab 770 includes only one frangible bonding agent 772disposed on the engaging member 771. The tape tab 770 of FIG. 7A may befolded laterally inwardly such that the frangible bonding agent 760contacts a portion of the absorbent article 760 or another portion ofthe tape tab 770. In the example shown in FIG. 7B, a first frangiblebonding agent 772 is disposed on the engaging member 771 and a secondfrangible bonding agent 772 is disposed on the non-engaing member side775 of the tape tab 770. The tape tab 770 of FIG. 7B may be foldedlaterally inwardly, such that the first frangible bonding agent 772contacts a first portion of the tape tab 770 or article 760 inboard ofthe engaging member. The tape tab 770 of FIG. 7B may then be foldedlaterally inwardly a second time such that the second bonding agent 772contacts a second portion of the tape tab 770 or article 760 inboard ofthe first portion. It is to be understood that, with regard to FIGS. 7,7A, and 7B the term inboard refers to the relative positions of elementswhen the article 760 and the tape tabs 770 are viewed in a flat-outconfiguration (i.e., not folded).

FIG. 8 shows another example of an absorbent article 860 comprising apair of opposing tape tabs 870. The absorbent article 860 may alsoinclude one or more pair of opposing ears 865 to which the tape tabs 870are joined, as shown in FIG. 8. The ear 865 may include an activatedportion 890 that provides at least some elasticity or extensibility tothe ear 865. The tape tab 870 may be joined to the ear 865 at a bondedportion 802 by any means known in the art (e.g., adhesive, pressure,thermal, or ultrasonic bonding). The tape tab 870 may include anengaging member 871 and a gripping portion 873. Broken-line circle 8Adesignates the portion of the tape tab 870 shown in FIG. 8A. As seen inFIG. 8A, the tape tab 870 may include a frangible bonding agent 872disposed on the gripping member 873. Alternatively or additionally, thefrangible bonding agent 872 may be applied to the middle portion 803 ofthe tape tab 870 or even the bonded portion 802.

Bonded Fastening System

The bond strength of an engaged fastening system that has been foldedaccording to the process described herein may be characterized in termsof an opening force (Initial or Aged), a Modified Opening Force (Initialor Aged), or a shear force. Suitable values for Opening Force, ModifiedOpening Force, and Shear Force, as well as the method for measuringthese values are described in copending U.S. Provisional Ser. No.61/184,102. For example, a suitable Aged Modified Opening Force and/orAged Opening Force for the fastening systems and/or frangible bondsdescribed herein may be less than 8N; 5N; 2 N; 1.5 N; 1 N; 500 mN; oreven less than 100 mN, but greater than 0 N. Table 1 below illustratesthe crossover temperatures of several bonding agents. The first bondingagent is a fugitive hot-melt adhesive sold under the product codePHO-3005. The second bonding agent is a fugitive hot-melt adhesive soldunder the product code PHO-3000. The third bonding agent is a permanenthot-melt adhesive sold under the product code D-3166. All threeadhesives are available from H.B. Fuller. The crossover temperature ofeach bonding agent is determined according to the RheologicalMeasurement Test, except that the plate gap target is 1,789 μm forPHO-3000 and 1,743 μm for PHO-3005.

TABLE 1 Bonding Crossover Agent Temp (T_(x)) PHO 3005 58-62° C. PHO 300045-50° C. D3166 73-77° C.

Table 2 below illustrates the effect that temperature and/or pressuremay have on the bond strength of an adhesive. PHO-3000 and PHO-3005 areboth fugitive adhesives available from H. B. Fuller, while H2401 is apermanent bonding adhesive available from Bostik. For samples containingadhesive, the adhesive is applied to the center of the hook materialshown in Table 3 (i.e., product code 963 from Aplix, product codeXHK01084 from 3M, or product code XHK02897 from 3M) as a 15 mmcontinuous line having a nominal width of 1 mm in a directionsubstantially parallel to the MD. A sample of hook material thatincludes no fugitive adhesive is designated as “None” in Table 3 and isused as a control. The hook samples shown in Table 2 are attached to adiaper ear such as the diaper ear 265 illustrated in FIG. 2. In thisexample, the ear is an activated (i.e., incrementally stretched),four-layer laminate of a 65 micron film sandwiched between a layer of 27gsm carded nonwoven and a layer of 17 gsm SMS nonwoven, and a 40 gsmspunbond nonwoven layer joined to the 27 gsm nonwoven layer. In order toobtain Aged Opening Force values, the samples are conditioned asfollows. A first bifolded size 4 PAMPERS CRUISERS brand disposablediaper is placed at the bottom of a LEXAN brand polycarbonate box havinga storage space that is 45 mm deep, 165 mm long and 125 mm wide. Asecond bifolded size 4 PAMPERS CRUISERS brand disposable diaper isplaced on top of the first diaper in the container. The second diapermay contain up to five sample substrates (i.e., ears), which are placedinside the diaper (i.e., between the bifolded portions). Up to threesample containing diapers may be stacked on top of the bottom diaper inthis fashion. A final bifolded size 4 PAMPERS CRUISERS brand disposablediaper is placed at the top of the stack of diapers in the box (for atotal of up to five diapers). A lid is placed over the top of the stackof diapers and secured such that there is no gap between the lid and thetop of the walls of the box. It is believed that this configurationsimulates the typical storage pressure experienced by a diaper in acommon flow wrap type package. The compressed samples are conditionedaccording to the temperatures and times shown in Table 3. The InitialOpening Force values shown in Table 3 are determined according to theOpening Force Test, within one hour after the adhesive shown in Table 3is applied to the sample. The Aged Opening Force shown in Table 3 isobtained from samples that are conditioned as described above andsubsequently tested according to the Opening Force Test.

TABLE 2 Aplix 963 3M XHK01084 3M XHK02897 Opening Standard OpeningStandard Opening Standard Adhesive Force (N) Deviation N Force (N)Deviation N Force (N) Deviation N PHO- Initial: 3.84 1.66 10 Initial:3.89 2 10 Initial: 6.56 1.81 10 3005 Aged: 1.31 0.4 10 Aged: 1.38 0.9910 Aged: 2.69 0.87 10 PHO- Initial: 3.77 2.75 10 Initial: 4.11 3.08 10Initial: 7.97 2.1 10 3000 Aged: 1.18 0.4 10 Aged: 1.48 0.6 10 Aged: 1.640.33 10 H2401 Initial: 3.73 0.44 10 Initial: 5.84 0.72 10 Initial: 5.191.15 10 Aged: 4.84 1.01 10 Aged: 7.04 0.9 10 Aged: 6.44 0.78 10 NoneInitial: 0.62 0.14 10 Initial: 0.76 0.35 10 Initial: 1.08 0.33 10 Aged:0.53 0.09 10 Aged: 0.83 0.86 10 Aged: 0.75 0.34 10

As can be seen from Table 2, only the fugitive adhesives provide adecrease in Hook Opening Force when aged, while the permanent bondingH2401 adhesive shows an undesirable increase in Hook Opening Force whenaged.

Test Methods

Unless otherwise indicated, all test methods and material or sampleconditioning are performed at a temperature of 23° C.±2° C. and arelative humidity of 50%±2%.

Opening Force Test

This method may be used for measuring the opening force of a firstsubstrate bonded to a second substrate by determining the amount offorce required to separate the substrate surfaces that are bonded to oneanother. The Opening Force Test is used to determine the Initial OpeningForce value of a pair of bonded substrates by testing the pair of bondedsubstrates within one hour of the substrates being bonded to oneanother. The Opening Force Test is also used to determine the AgedOpening Force value of a pair of bonded substrates by testing the pairof bonded substrates more than 72 hours after the substrates are bondedto one another. The surface of a substrate that is opposite a bondedsurface of that substrate is referred to in this method as a non-bondedsurface. In certain embodiments, such as those including a foldedsubstrate, the first substrate may be unitary with the second substrate.While this method may describe various exemplary configurations forbonded substrates, such as a diaper ear and/or fastening tab, it is tobe understood that one of ordinary skill in the art could readily adaptthis method to test the opening force of any bonded substrate.

The opening force of a bonded pair of substrates is measured using anMTS Alliance with TestWorks 4 software available from MTS Systems Corp.,Eden Prairie, Minn., or equivalent, fitted with a suitable load cell.The load cell should be selected such that the maximum force attained inthe test is between with 10% and 90% of the stated maximum load of theload cell. The jaws of the tensile tester must have flat surfaces andmust be at least 25 mm wide. Also, the jaws should provide adequateforce to ensure that the sample does not slip during testing. Additionaldetails regarding suitable test apparatus, calibration procedures, etc.are given in ASTM D76-99 (Standard Specification for Tensile Testing forTextiles).

Sample Preparation:

-   -   1. If the bonded portion of the first and second substrates is        incorporated into a finished product, carefully remove first and        second substrates from the article (e.g., by cutting with        scissors) while ensuring that there is substantially no peel or        shear load on the bond to be tested.    -   2. If the sample contains exposed adhesive that is not a part of        the bond between the first and second substrates, care must be        taken to avoid allowing this adhesive to introduce artifacts        into the data. Exposed adhesive should be deactivated, for        example, by lightly coating it with talc or corn starch.    -   3. If either of the first or second substrates is extensible,        render it substantially inextensible by applying backing tape        (e.g., masking tape sold under the product code 410 by 3M) over        the entire non-bonded surface of the material.    -   4. If the first and second substrates each extend at least 50 mm        outwardly from the bond, then proceed to testing as detailed        below. These extending portions are referred to as “tails.” If        the first and second substrates do not each have a tail that is        at least 50 mm long, then make a tail by adding a leader made        from standard, office masking tape such as SCOTCH 2600 brand        masking tape available from 3M to the first and/or second sample        substrate. To make a tail by attaching a leader, perform the        following.

Secure the tape to the non-bonded surface of the substrate such that theleader will extend at least 50 mm from the edge of the bond when theleader is folded back onto itself, for example, as shown in FIGS. 9B and9C. Fold the leader 1460 back onto itself and join it to the bondedsurface 1412 of the first substrate 1410 such that at least 5 mm of theleader 1460 overlaps itself and the bonded surface 1411. However, in anysample 1400 in which the bond is less than 10 mm from the relevantsubstrate edge, do not overlap the leader 1460 and the bonded surface1411 of the substrate (i.e., only join the leader to itself as shown inFIG. 9C). FIG. 9A shows an example of a sample 1400 prepared without anadded leader. The sample 1400 includes a first substrate 1410 having abonded surface 1411 and a non-bonded surface 1412. The first substrate1410 is bonded to a second substrate 1420, which also has a bondedsurface 1421 and a non-bonded surface 1422. The first and secondsubstrates 1410 and 1420 extend in the x-direction and are joined to oneanother by a bond 1430 (e.g., a frangible bond formed by a fugitiveadhesive). In FIG. 9A, the distance A from the edge of the bond 1430 tothe edge 1440 of the sample 1400 is greater than 50 mm.

Thus, no leader is needed for the sample 1400 shown in FIG. 9A. FIG. 9Bshows an example of a sample 1400 prepared with a leader 1460. In FIG.9B, the exemplary sample 1400 includes a first and second substrate 1410and 1420, respectively, that are unitary. That is, the first and secondsubstrates 1410 and 1420 are formed from the same piece of material, forexample, by folding the material over itself. The first substrate 1410includes engaging elements 1450. The first substrate 1410 is joined tothe second substrate 1420 by a frangible bond 1430 between the engagingelements 1450 and the bonded surface 1421 of the second substrate 1420.The distance B between the edge 1445 of the first substrate 1410 and theedge of the bond 1430, as shown in FIG. 9B, is greater than 10 mm butless than 50 mm. Thus, a leader 1460, which overlaps itself and thefirst substrate 1410, is affixed to the bonded side 1411 and thenon-bonded side 1412 of the first substrate 1410. As shown in FIG. 9B,the leader 1460 does not overlap the engaging elements 1450 disposed onthe bonded side 1411 of the first substrate 1410. The distance C fromthe edge of the bond 1430 to the edge 1455 of the second substrate 1420is greater than 50 mm, and thus no leader is required. FIG. 9C shows anexample of a sample 1400 prepared with no overlap between the leader1460 and the bonded surface 1411 of the first substrate 1410. Thedistance D from the edge 1445 of the first substrate 1410 to the edge ofthe bond 1430, as shown in FIG. 9C, is less than 10 mm. In this case, aleader 1460 is affixed to the non-bonded side 1412 of the firstsubstrate 1410 and then folded over such that the leader 1460 overlapsitself but not the bonded side 1411 of the first substrate 1410. Thedistance E from the edge of the bond 1430 to the edge 1455 of the secondsubstrate 1420 is greater than 50 mm, and thus no leader 1460 isrequired.

-   -   5. If the sample extends more than 25 mm beyond the y-direction        ends of the bond (see e.g., FIG. 2 for location of y-direction        ends), the excess material is to be removed (e.g., cut off) in a        manner which places substantially no shear or peel load on the        bond to be tested.

Opening Force Testing of Prepared Sample.

-   -   1. Set the spacing of the tensile testers' jaws (gauge length),        such that the jaws of both clamps are at least 25 mm from the        edge of the bond, when the sample is mounted with a tail in each        of the upper and lower jaws, and with the bonded portion        extending laterally midway between the jaws. Position the sample        in the jaws such that there is no substantial shear or peel        force being applied to the bond to be tested. In addition,        position the sample such that there is substantially equal        distance between the bond and the upper and lower jaws.    -   2. Insert the tails into the respective jaws and ensure that the        tails are centered in the jaws with no portion of the sample or        leader extending beyond the grip. The sample should not be under        tension, but should have minimal slack.    -   3. Ensure that the grips are suitably tight to prevent slippage,        and zero the crosshead location.    -   4. Initiate the test at a crosshead speed of 305 mm/minute with        collected into a data file at a resolution of approximately 10        data points per mm.    -   5. Data collection is to stop either 10 mm of crosshead travel        after the bond is broken or immediately prior to encountering        any obstruction which would obscure determining the force to        break the bond. For example, an obstruction could be the fold of        a folded tape tab or an unrelated bond between the first and        second substrates such as a bond fusing the two substrates        together.    -   6. If a leader tears or delaminates from the substrate to which        it is attached prior to the bond breaking and the peak load        force is greater than 8N, then record the observed peak load        force. If a leader tears or delaminates from the substrate to        which it is attached prior to the bond breaking and the peak        load force is not greater than 8N, then discard the data and        retest using a new sample, which has been reinforced by applying        backing tape as described above.    -   7. Repeat the test until 10 samples have been successfully        tested. Record the individual peak load forces and average them        to obtain the Initial Opening Force value or Aged Opening Force        value, as appropriate.

Coupon Peel Test

The object of this test is to measure the change in bond strength of aparticular bonding agent over time as observed on a particularsubstrate. This method may be used to test the bond strength provided bya bonding agent harvested from a finished product or a virgin bondingagent (i.e., a bonding agent that has not been incorporated into anarticle).

Harvested Adhesive: Using a razor blade, small spatula, thermal knife,or other suitable tool, carefully remove adhesive to be tested from afinished product and place into a suitable container (e.g., by scrapingor melting the adhesive off of the finished product and into a containersuch as a laboratory weigh boat or glass container). Care should betaken to minimize inclusion of substrate fragments, fastener fragments,or other contaminants in the sample to be tested. Check the sample priorto testing and remove any contaminants which may be present. Obtainsufficient adhesive to perform the test below (e.g., approximately 50 mgor 0.56 g per test run, depending on the test).

Virgin Adhesive: virgin adhesive obtained from a supplier may requirehomogenization before testing if the outer wrap is part of the adhesiveformulation, which is not uncommon. If this is the case, melt theadhesive and wrapper together at 175° C. in the lab-oven. Stir theadhesive from time to time with a metal spatula by hand to homogenize.After homogenization pour the adhesive onto silicone-treated releasepaper and let it cool down to ambient temperature. If the adhesive doesnot require homogenization, then proceed directly to the test procedure.

Procedure

-   -   1. Prepare cut samples of 2 mil corona-treated PET film        (polyethylene terephtalate) film (commercially available from        Filmquest Group Inc, Bolingbrook, IL USA) by cutting the film        into rectangular pieces of 65×100 mm.    -   2. Obtain two, flat, aluminum plates (12.7 ±2 mm thickness) and        having dimensions of 150 mm×305 mm.    -   3. Pre-heat a Carver Press (e.g., model 3853-0 available from        Carver Inc., Wabash, Ind. USA) and the two aluminum plates to        177° C. Stack the two aluminum plates one on top of the other        with edges aligned on the bottom platen of the press and close        the press to 345 MPa +/−690 kPa.    -   4. Pre-weigh 0.035-0.045 g of the harvested or virgin adhesive        into a laboratory weigh boat or other suitable container    -   5. Obtain release paper (e.g., 40-pound release liner        commercially available from American Coated Products,        Zionsville, IN USA) sized such that the PET film samples can be        placed entirely within the bounds of the release paper, but the        release paper does not extend past the edges of the aluminum        plates. Place a strip of the PET film corona-treated side up        onto the release-coated side of a sheet of the release paper.        Pour or place the adhesive onto the center of the PET film. Use        a metal spatula to center the adhesive on the film.    -   6. Place a second strip of the PET film on top of the adhesive        such that the corona-treated side of the PET film faces the        adhesive. Place a second layer of release paper, release-coated        side down, on top of the PET film-adhesive sandwich    -   7. Open the Carver press' platens sufficiently to remove the top        aluminum plate, while leaving the bottom aluminum plate on the        bottom platen of the press    -   8. Place the sample from step 5 onto the bottom aluminum plate,        taking care to avoid dislocating the adhesive from its original        position between the PET film layers.    -   9. Place the top aluminum plate on top of the paper-PET-adhesive        sandwich disposed on the bottom aluminum plate. Use care to keep        the sandwich of materials horizontal and avoid displacing the        release paper and PET film in a way that could displace the        adhesive from between the layers of PET film.    -   10. Close the Carver press platen to a pressure of 345 MPa        +/−690 kPa. Wait 20 seconds. Then open the press to a sufficient        gap to remove the stacked aluminum plates with the material        sandwich still positioned between them. Again, keep the plates        horizontal and use care to avoid displacing the release paper        and PET film.    -   11. Gently remove the top plate and place the release paper-PET        film-adhesive sandwich onto a horizontal room temperature        surface.    -   12. Allow the sample to cool for at least 10 minutes but not        more than 30 minutes then use a razor to cut just the        PET/Adhesive sandwich into a 25 mm wide test specimen centered        within the 65 mm PET width. The final test specimen is therefore        25×100 mm. Use care to avoid debonding the adhesive from the PET        layers.    -   13. The peel force of the PET/Adhesive sandwich is measured        using an MTS Alliance with TestWorks 4 software available from        MTS Systems Corp., Eden Prairie, Minn., or equivalent, fitted        with a suitable load cell. The load cell should be selected such        that the maximum force attained in the test is between with 10%        and 90% of the stated maximum load of the load cell. The jaws of        the tensile tester are selected to have flat surfaces and are at        least 25 mm wide. Also, the jaws should be configured or        selected to provide adequate force to ensure that the sample        does not slip during testing. Additional details regarding        suitable test apparatus, calibration procedures, etc. are given        in ASTM D76-99 (Standard Specification for Tensile Testing for        Textiles).    -   14. Set the spacing of the tensile testers' jaws (gauge length)        to 60 +/−1 mm. Set the cross-head speed to 5.0 mm/min.    -   15. Mount the sample in the jaws of the tensile tester such that        one PET strip is clamped in the top jaw and the other strip is        clamped in the bottom jaw. Use the unbounded ends of the PET        strips to do this while using care to avoid de-bonding the        center of the strips from the adhesive. The sample should not be        under tension, but should have minimal slack.    -   16. Ensure that the grips are suitably tight to prevent        slippage, and zero the crosshead location.    -   17. Initiate the test at a crosshead speed of 5 mm/minute with        collected into a data file at a resolution of approximately 10        data points per mm.    -   18. Data collection is to stop after the adhesive to PET bond is        broken completely. Report the peak load during the test    -   19. Repeat the test until at least 3 samples have been        successfully tested. Record the individual peak load forces and        average them to obtain the Average Peel Force.

Rheological Measurement Test

The object of this test is to determine the crossover temperature of acomposition. This method may be used to test an adhesive sampleharvested from a finished product or a virgin adhesive sample. Refer tothe Coupon Peel Test above for preparing virgin and harvested adhesivesamples.

Equipment:

-   -   Air-circulating lab-oven or chamber capable to be controlled up        to 200° C. (+/−3° C.) (e.g., Carbolite air circulating oven,        Peak series, model PF60 with temperature control unit Eurotherm        2416CC)    -   Lab-Balance which allows precision of 0.01 g (e.g., Mettler        PG503-S or equivalent)    -   TA Instruments Advanced Rheometer series AR2000 with Peltier        temperature option, TA Instruments Corporation, New Castle,        Del.; with 25 mm flat parallel plate geometry consisting of an        upper steel plate (diameter: 25 mm) and a lower Peltier or        heating plate enabling temperature control. The rheometer is        capable of applying temperatures of from −5° C. to 170° C. with        a precision of 0.5° C. and torques up to 200 milliNewton meters        (mNm) with a precision of 0.1 mNm.

Test Procedure: Geometry Gap Setting:

-   -   1. Set the temperature of the Peltier or heating plate of the        rheometer to 120° C.    -   2. Calibrate the zero gap at 120° C.    -   3. Set the geometry gap to 2000 micrometers.    -   4. Weigh out 0.56 g +/−0.01 g of adhesive and place it onto the        center of the Peltier or heating plate of the rheometer and set        the temperature to 120° C.    -   5. After approximately ⅔ of the amount of adhesive is molten,        slowly lower the upper plate to the geometry gap of 2000        micrometer. The velocity of the rheometer head must not exceed        1000 micrometers per second in order to achieve good contact        between the adhesive and the upper plate without damaging the        adhesive sample.    -   6. Cover the geometry with the geometry cover—i.e., solvent trap        cover—for 2 minutes so that the upper plate can heat up and the        adhesive gets completely molten.    -   7. Remove the cover and rotate the upper plate manually to        distribute the adhesive evenly between the upper plate and the        Peltier or heating plate. Ensure full contact of the adhesive to        the upper plate. Afterwards cover the geometry again for another        2 minutes.    -   8. Remove the cover and check whether the adhesive is        distributed evenly. If it is not, repeat point 7. If it is,        cover the geometry again and continue with point 9.    -   9. Perform a pre-shearing at a frequency of 2.5 radians per        second and an oscillatory strain amplitude of 1% for 4 minutes        to condition the adhesive.    -   10. After pre-shearing keep the temperature at 120° C. for 1        minute to let the adhesive settle and recover from pre-shearing.    -   11. Ensure the geometry and adhesive are thermally equilibrated        by maintaining the setup at 120° C. for more than 2 minutes        without any application of stress.

Temperature Sweep Execution:

Perform a temperature sweep starting at 120° C. and cooling down to −5°C. at a cooling rate of 3° C. per minute. Set the frequency to 10radians per second and the commanded oscillatory strain amplitude to26%. The apparent storage modulus (G′), apparent loss modulus (G″) andthe apparent loss tangent (Tan 6) are recorded as a function oftemperature. Note that the commanded strain may not be achieved,especially at lower temperatures, and that the strain may exceed thelinear elastic region of the adhesive composition. The apparent valuesare the respective values recorded by the instrument notwithstandingthese conditions.

Calculation/Reporting:

From the temperature sweep report the following parameters: cross-overtemperature in ° C. (1 decimal place). The cross-over-temperature isfound at the end of the rubber-plateau towards higher temperaturesindicating the beginning of the terminal zone. At the cross-overtemperature, the apparent storage modulus and apparent loss modulusvalues are equal and the apparent loss tangent value is 1.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A method for folding a fastener during a highspeed manufacturing process and maintaining the folded fastener in afolded configuration throughout the high speed manufacturing process,the method comprising: obtaining an article comprising a foldablefastener and moving said article in a machine direction during the highspeed manufacturing process, said high speed manufacturing processhaving a cross direction orthogonal to said machine direction, saidfoldable fastener comprising a web with first and second opposingsurfaces, and at least one engaging member joined to the web; applying afrangible bonding agent that comprises a fugitive adhesive to a firstportion of the first surface of the fastener; and folding the fastenersuch that the frangible bonding agent contacts a second portion of thefirst surface of the fastener; and wherein the fastener is a hook/looptype mechanical fastener; wherein the engaging member includes aplurality of hooks with gaps between adjacent hooks, and the webincludes a plurality of receiving elements that are engageable with thehooks; and wherein the frangible bonding agent forms a substantiallyunbroken line that penetrates at least partially into one or more of thegaps between adjacent hooks.
 2. The method of claim 1, wherein thefolded fastener has an Initial Opening Force value of greater than about2 N according to the Opening Force Test.
 3. The method of claim 1,wherein the folded fastener has an Aged Opening Force value of less thanabout 8 N.
 4. The method of claim 1, wherein the fastener is folded suchthat the frangible bonding agent contacts a second portion of the firstsurface of the fastener and forms a bond between the first and secondportions of the first surface.
 5. The method of claim 1, wherein thefastener is folded in the cross direction along a line extending in themachine direction.
 6. The method of claim 5, wherein the folded fasteneris subjected to compression.
 7. The method of claim 1, wherein thefastener includes a fastening tab and the engaging member is disposed onthe fastening tab.
 8. The method of claim 1, wherein the engaging memberis joined to the fastener at a base and the frangible bonding agent isnot applied to the base.
 9. The method of claim 1, wherein the frangiblebonding agent is applied in a pattern selected from the group consistingof one or more substantially straight lines, an s-shape, a z-shape, ac-shape, a broken line, a t-shape, a cross-shape, spiral-shape,omega-shape, dots and combinations of these.
 10. The method of claim 1,wherein the fugitive adhesive has a strength decay of between about 20%,and 100% according to the Coupon Peel Test.
 11. The method of claim 1,wherein the fugitive adhesive has a strength decay of between about 30%and 70% according to the Coupon Peel Test.